Silicon process technology continues to shrink the feature size of devices causing more process variation. As a result, charged-based memory storage technologies, such as dynamic random access memory (DRAM), may no longer scale with successive technology generations.
Phase change memory (PCM) is a potential replacement for DRAM in computers and other digital devices. Like many other non-volatile memories, PCM has a limited lifetime or durability. Typically, over time, one or more cells of the blocks of a PCM device may become stuck and can no longer be reliably written to.
Multi-level cell (MLC) PCM has the added challenge of cell drift. After the cell is programmed, the absolute value of the cell can drift, increasing the cell's resistance over time. MLC PCM wears out much faster than DRAM, making solutions that extend the life of the MLC PCM block and the capacity of the MLC PCM memory system desirable. Other memory technologies may have similar issues, such as Conductive Bridging RAM (CBRAM), for example.